[PATCH 5.4 16/80] xtensa: use MEMBLOCK_ALLOC_ANYWHERE for KASAN shadow map

From: Greg Kroah-Hartman
Date: Thu Dec 19 2019 - 13:59:12 EST


From: Max Filippov <jcmvbkbc@xxxxxxxxx>

commit e64681b487c897ec871465083bf0874087d47b66 upstream.

KASAN shadow map doesn't need to be accessible through the linear kernel
mapping, allocate its pages with MEMBLOCK_ALLOC_ANYWHERE so that high
memory can be used. This frees up to ~100MB of low memory on xtensa
configurations with KASAN and high memory.

Cc: stable@xxxxxxxxxxxxxxx # v5.1+
Fixes: f240ec09bb8a ("memblock: replace memblock_alloc_base(ANYWHERE) with memblock_phys_alloc")
Reviewed-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Signed-off-by: Max Filippov <jcmvbkbc@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/xtensa/mm/kasan_init.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/arch/xtensa/mm/kasan_init.c
+++ b/arch/xtensa/mm/kasan_init.c
@@ -56,7 +56,9 @@ static void __init populate(void *start,

for (k = 0; k < PTRS_PER_PTE; ++k, ++j) {
phys_addr_t phys =
- memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
+ memblock_phys_alloc_range(PAGE_SIZE, PAGE_SIZE,
+ 0,
+ MEMBLOCK_ALLOC_ANYWHERE);

if (!phys)
panic("Failed to allocate page table page\n");